.TH std::ferror 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::ferror \- std::ferror

.SH Synopsis
   Defined in header <cstdio>
   int ferror( std::FILE* stream );

   Checks the given stream for errors.

.SH Parameters

   stream - the file stream to check

.SH Return value

   Nonzero value if the file stream has errors occurred, 0 otherwise.

.SH Example


// Run this code

 #include <clocale>
 #include <cstdio>
 #include <cstdlib>
 #include <cwchar>

 int main()
 {
     const char *fname = std::tmpnam(nullptr);
     std::FILE* f = std::fopen(fname, "wb");
     std::fputs("\\xff\\xff\\n", f); // not a valid UTF-8 character sequence
     std::fclose(f);

     std::setlocale(LC_ALL, "en_US.utf8");
     f = std::fopen(fname, "rb");
     std::wint_t ch;
     while ((ch=std::fgetwc(f)) != WEOF) // attempt to read as UTF-8
         std::printf("%#x ", ch);

     if (std::feof(f))
         puts("EOF indicator set");
     if (std::ferror(f))
         puts("Error indicator set");
 }

.SH Output:

 Error indicator set

.SH See also

   clearerr clears errors
            \fI(function)\fP
   feof     checks for the end-of-file
            \fI(function)\fP
   fail     checks if an error has occurred
            \fI(public member function of std::basic_ios<CharT,Traits>)\fP
   C documentation for
   ferror
